Carbonizing-box, annealing-pot, and similar article



' 'qualitles.

WILLIAM E. JEANNOT, 0F IVIUSKEGON, MICHIGAN, ASSIGNOR TO WEST MICHIGAN STEEL FOUNDRY 00., OF MUSKEGON, MICHIGAN, A CORPORATION OF MICH- IGAN.

CARBONIZING-BOX, ANNEALING-POT, AND SIMILAR ARTICLE.

cles composed of a ferrous alloy having a high melting point, and especial capacity to resist heat or oxidation, carbonization,

and changes in shape.

The chief object of the invention is to provide carbonizingboxes and the like, made of a relatively inexpensive alloy, so that they incorporate the above mentioned qualities to a marked degree.

The desired qualities are embodied in an alloy in accordance with my invention, by adding to iron or steel by any suitable process, silicon, carbon and manganese, and usually also phosphorus and sulfur, in suitable proportions.

My experiments have shown that either iron or steel treated with silicon, with carbon and manganese in suitable, proportions, will become more and more heat resistant andcementation resistant as the silicon content is increased from 1% to 3.5%. I have not made alloys higher" than 3.5% silicon but myexperience leads me to believe that alloys up to 5% or 6% will possess the same The following table shows variations of the ingredients Which will produce the above qualities:

Carbon .10 to .50 Silicon 1.50 to 3.50 Manganese '.2 to .6

Phosphorus under .04 Sulfur under .04

The followingtable shows a Wider range of variation of certain of the ingredients which will give desirable results in certain cases:

Carbon .0' to .50 Silicon 1.0 to 6.00 Manganese .10 to .8

Phosphorus under .04 Sulfur under .04

I have found that the following formula,

Specification of Letters Patent.

Patented dune 7, 192a.- 1920. Serial No. 381,775.. r

with more restricted ranges of silicon, manganese and carbon produces a carbonizing box or like receptacle having, to a marked degree, the qualities of resistance to heat, warping, oxidation, carbonization and cementation:

Silicon Q 2.5 to3.

Manganese .2 to .6 Carbon .1 to .2 Phosphorus under .04% Sulfur under. .04%

The most important element of the alloy for the present purpose is silicon. The element of second importance is manganese. The element of third importance is carbon. The phosphorus and sulfur are of smallimportance except from a standpoint of molding. The percentage of these elements is kept low to prevent checking of the castings.

The action of the alloying ingredient in producing the desired result cannot becompletely accounted for in the present knowledge of the art.

I have, however, demonstrated after study and experiment, by thorough tests under working conditions, that alloys composed as stated will embody the desired qualities to a marked degree.

Carbonizing boxes composed of a steel alloy produced within the range of the above formulas have a very high melting point, approximately 2600 F are also highly resistant to oxidation in the presence of an oxidizing flame, and are also highly resistant to carbonization or cementation; that is theywill absorb carbon very slowly incomparison with steels of other composition when in the presence of carbonizing material.

Therefore, although the alloy is valuable for many purposes where the above qualities are desired, it .is especially valuable for carthe same time absorb the carbonizing material which they contain, and they also are readily oxidized by contact with the flame and oxygen of the furnace. The principal effect of this oxidation is to render the boxes porous so that they are either entirely ruined in a relatively small number of heats, or waste a large part of the carbonizing material, which must be gasified for the purpose of combining with the articles which are being treated; and if use of these defective boxes is continued they must .be retained in the furnace for a longer time in order to properly treat the metallic contents.

Certain alloys have been proposed for car-- bonizing boxes and the like which as a rule, depended upon a relatively expensive ingredient, such as nickel, to im art the desired qualities to the alloy. T e most significant content of my alloy, as above stated, is silicon, which is relatively inexpensive, and I am able to produce carbonizing boxes and other articles which are equal, if not superior, to any other alloys in the qualities named, at a much lower cost.

An increase in the silicon content within reasonable limits, as suggested in the preceding formulas, increases the resistance of the alloy to heat and to carbonization, or cementation. A decrease in the manganese content within reasonable limits, as above suggested, increases the resistance of the alloy to cementation. Decrease in the carbon content within reasonable limits raises the melting point of the alloy.

So far as I am informed no alloy of simi-- lar composition has been suggested for carbonizing boxes and like articles; therefore while silicon, carbon and manganese are frequently ingredients in ferrous alloys they have not been employed in a combination equivalent to the present one, or in such a way as to produce the desired results.

This application is a continuation in part of my previous application Serial Number 340,443, filed November 25, 1919, including the subject matter of that application, with the addition of a slightly increased range of manganese.

Having thus fully described my invention, what I claim is:

1. A. carbonizing box or like container composed of ferrous alloy having as a leading ingredient silicon in proportion from 1 to 6%, together with carbon and manganese.

2. A carbonizing box or like container composed of a ferrous alloy having as a leadlng ingredient silicon in proportion from 1 to 6%, together with carbon, 'manganese, phosphorus and sulfur.

3. A carbonizing box or the like having a very high melting point and great resist ance to oxidation and carbonization, con sisting of a ferrous alloy including silicon l to 6%, manganese .10 to .8% and carbon .0 to 50%.

4. A carbonizing box or the like having a very high melting point and great resistance to oxidation and carbonization, consisting of a ferrous alloy including silicon 1.50 to 3.50%, manganese .30 to .8% and carbon .10 to 50%.

5. A carbonizing box or the like having a very high melting point and great resistance to oxidation and carbonization, consisting of a ferrous alloy including silicon 1 to 6%, manganese .10 to .8% and carbon .0 to .50%, phosphorus and sulfur each 04% or less.

6. A. carbonizing box or the like having a very high melting pointand great resistance to oxidation and carbonization.consisting of a ferrous alloy including silicon 1.50 to 3.50%, manganese .30 to 6% and carbon .10 to .50, phosphorus and sulfur each 04% or less. I,

7. A carbonizing box or like article adapted to contain articles for heat treatment at high temperature composed of a steel alloy having the following significant ingredients in addition to the iron content; silicon 2.5 to 31%. manganese .3 to 8%, carbon .1 to 2%, sulfur and phosphorus each 04% or less.

8. A carbonizing box or similar container for treating articles at high temperature, highly-resistant to heat, oxidation and carbonization, composed of a silicon-alloy-steel, containing silicon in proportion from approximately 1. to 6%.

In testimony whereof l aflix my signature in presence of two witnesses.

WILLIAM E. J EANN OT.

Witnesses:

JOHN Q. Ross, Arron Wmson. 

